Masket notes that CA, WA and CO all have very right Republicans and left Democrats. I think the commonality here is these are all states with large proportions of in-migrants from elsewhere in the U.S. who are disproportionately young renters in large cities, and also (in contrast) very large swathes of low population density land with multi-generation residents who own their homes and work in agriculture or resource extraction. (Original post here.)